A wide variety of medical devices have been developed for medical use. Some of these devices include an elongate shaft that has been ground along a portion of its length to give a desired profile. In particular, a common medical device having an elongate shaft is a guidewire. Guidewires are commonly used for intraluminal procedures to provide and define a pathway to a body site for treatment such as intravascular access to a blockage in a coronary artery, access to the biliary tree to sample tissue, or access to cerebral vasculature for treatment of an aneurysm. The guidewire defines and maintains the pathway to the treatment site to allow other treatment devices, such as balloon catheters or stent delivery catheters, to be routed quickly over the guidewire to the treatment site and continues to maintain the pathway during exchange of devices.
Certain balloon catheters also incorporate an elongate shaft as a core wire to provide stiffening over a portion of the catheter's length. The core wire may be ground to include a taper to adjust or change the flexibility in that region.
To be useful for the medical device applications described above, the wire used for form the guidewire or core wire must meet stringent specification with respect to size and straightness. Further, a change in profile may be desired over the wire's length in order to vary the flexibility of the device. Procedures have been developed to improve straightness and to create a desire profile. However, there is a need for improvement in these techniques to achieve tighter control over size, profile, and manufacturing costs.